Radiator core



March 20, 1934. w, w M 1,951,366

RADIATOR CORE Filed April 27, 1929 gulmnmummuriluml 3W"HEIWHHWMEWIHk I 0mm;

511ml "HUME- m" HIIUII E Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE 4 strips which are. preformed by crimping into This invention relates to the cores of radiators for the cooling systems of internal combustion engines or the like and has for its object to provide a more efficient construction which is less costly to manufacture than those heretofore proposed.

With these and other objects in view the invention consists in the novel details of construction and combinations of parts as will be more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawing forming a part of this specification in which like numerals designate like parts in all the views,-

Fig. l is a front elevational view somewhat diagrammatic illustrating a radiator for an automobile containing a core built along the lines presently to be described;

Fig. 2 is an enlarged section detail of a portion of the core and partly in section to better illustrate this invention;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 5 and looking in the direction of the arrows;

Fig. 4 is a side elevational view of a portion of one of the strips formed in accordance with this invention;

Fig. 5 is a horizontal sectional view taken as on the line 55 of Fig. 4 and looking in the direction of the arrows;

Fig. 6 is a longitudinal sectional view through one of the fins associated with the core unit; and

r Fig. 7 is a transverse sectional view of said fin taken as on the line 7-7 of Fig. 6 and looking in the direction of the arrows.

In order that this invention may be the better understood it is said that heretofore radiator core constructions have been such that either vertical or substantially horizontal water tubes have been formed which permit a passage of water therethrough with insufficient cooling thereof under some conditions. This has been caused by several factors such as inadequate dimensions or capacity, insufficient radiating surface for the transfer of heat from the cooling fluid to the atmosphere, a too direct passage for the cooling fluid through the radiator whereby insufficient time is given to the fluid for complete cooling thereof, and other factors which will be readily observed and understood by those skilled in the art. The purpose of this invention is to provide a construction which is somewhat similar to prior constructions in that the core units are made from extremely thin metal shapeswhichwill readily fit one another or which will fit separator strips provided therefor, all .to,v

the endthat the passage of cooling fluidfrom top to bottom or from side to side through the radiator core will be broken, interrupted, or other wise affected so that a transfer of more heat to the atmosphere is accomplished. Another object of this invention lies in providing a tubular construction resulting in a more rigid radiator as a whole than those heretofore proposed. A still further object. of the invention is to provide a construction offering less resistance butniore.

turbulence to the air passing through the core for absorbing the heat given off from the cooling This invention is applicable to radiators of either the down-flow, or cross-flow type, and is particularly applicable to radiators having substantially hexagonally formed air cells in its.

core, it being understood that other forms may be readily devised which will still fall within the limits of this invention. The actual formation of these cells should be described so that the invention may be the better understood and therefore the following is directed to a disclosure, of such construction.

Extremely thin sheets of soft metal, having high heat conductivity and such for example as copper or brass, are formed into narrow strips of about 2 to 3 inches width. This strip which is substantially continuous is fed from a rollthrough pressure rollers the surfaces of which constitute dies to impress in said strip a plurality of indentions 2 arranged in parallel rows extending lengthwise of the strip, each 'indention being transversely ofv cylindrical formation..

These rows are formed in groups of two or more as indicated, said groups being divided by projections constituting abutments 3 for a purpose presently to appear. During this formation the strip comes in. contact with folding dies which depress portions of the strip which are then bent toward each other to form fins 4 extending later,- ally from the plane of the main body of the strip indicated inFig. 2 by the dot and dash line 30. The ends of each fin are pinched together as at 5 to enable a tight closed joint to be made at said ends, but between said ends each fin is not so pressed, as a result of which a space 6 is provided into which the fluid to be cooled may pass, all as will be-more fully brought out hereinafter. The die treatment is such that in the completely rolled strip the cylindrically formed indentions will be continuous in a vertical row with the fins dise,

posed in planes at right angles to the coaxial alignment of said indentions.

The strip so formed is then cut into lengths preferably but not necessarily slightly more than twice the dimension of the finished core into which it is to be fitted. In other words, in the case of a down-flow radiator if the core as completed is to be about twenty-four inches in height then these strips could be cut into lengths of about fifty inches. The purpose of this is to permit these preformed strips to be folded upon themselves with the fins extending inwardly and the ends of the strip brought together and inter-' locked in a single joint, not shown but readily understood, whereby there is formed a core unit of a length equal to the height of the finished radiator and having opposite walls eachadapted to form one half of two adjacent water tubes.

A predetermined number of such units are then;

assembled to form the finished core indicated at.1 in Fig. 1 possessing the required heat conducting area- Division or separator strips are placed between and in contact with the fins of each unit as desired to assist in the radiation of heat as well as to strengthen the core. On the other hand aunit may consist of one half of that above described or, in other words, the preformed strip may be cut into lengths substantially equal to the height of the finished radiator core so that, when two such units are placed face to face as indicatedin Figs. 2 and 5 there will be formed therebetween the same water tube as would be formed when assembling two of the double walled units above described. The fins form portions of the wall structure of the air cells 8, the remain- 'der of the core unit and the separator strips forming the other walls of said cells. When the units .are assembled the indentions of two adjacent units will form between said units tubes 10.

to conduct thecooling fluid, such as water, from side to side or from top to bottom according to the type of the radiator-during which travel the heat form said fluid is abstracted and transferred to the air passing through the air cells. The formation of the radiator core unit strips maybe readily understood from the foregoing and with reference to prior issued patents such forexample as 1,169,481 granted Jan. 25, 1916 toHerbert C. Harrison for Process of making automobile radiator sections.

f Referring to Fig. 2 there is disclosed a radiator core construction in which a flat strip of very thin metal is employed which has been previously passed through forming rolls as above described T; to impress therein the rows of substantially transversely cylindrical indentions 2 with folds constituting fins 4 disposed transversely of the rows of indentions. From Fig. 4 it will be observed that in, the formation of the core units there are created flanges, crimps, or corrugations 12 at each side edge of the core strip, said crimps having plane surfaces for the purpose of securing one radiator core unit to its adjacent unit. That is to say, there are provided a plurality of these crimps 12 which are disposed relatively to form a' serrated edge on the strip, and the angularity of said crimps is such that when one 'unit is brought up against an adjacent unit the similarly formed crimps will interfit and form sides of the hexagonal air cells 8.

Radiator constructions are so .well known. that theabove will be readily understood by one skilled in the art particularly with reference to the drawing, but it might here be stated that these preformed strips are either folded back upon themselves or otherwise held in spaced relation and a separator strip as indicated at 15 is inserted between the opposing fin portions of the strip and against which the fins 4 will contactingly rest so that as the heated fluid, such as water, courses down the water tube 10 as indicated by the arrows in Fig. 2 the heat from said water will be taken up by the thin metal of the core and this heat will be transferred through the fins 4 and separator plate 15 to the atmosphere which is passing through the spaces 8 known as the air cells of the radiator. In other words, by the foregoing description it will be understood that a core is formed providing closed water passages 10, and openings 8 for the atmosphere which are not closed attheir ends, whereby said atmosphere is free to pass through said spaces and over the surfaces of the metal forming the radiator core. Such a separator strip as herein described is disclosed in the U. S. Letters Patent 1,220,745 granted March 27, 1917 to Herbert C. Harrison and entitled Automobile radiator, said strip being shown in Fig. 10 of said patent.

In Patent 1,442,565 granted January 16, 1923 to Herbert C. Harrison and entitled Radiator core there is disclosed a construction in Fig. 4 of a straight wall water passage with adjacent separator strip. The purpose of this invention is to provide an improvement of'the construction as shown in said patent. In other words, in Fig. 4 of said patent there is a straight wall water tube 21 formed of core strips which have been precrimped and bent in such manner as to form the cylindrical indentions 13 which correspond to the indentions 2 of this invention, and there have been likewise formed laterally extending fins 10 which, however, are differently formed from the fins of this invention. By comparing the two figures of the drawing it will be seen that the fin 10 commences in the tangential plane of the cylindrical indentions 13 whereas by this invention the plane of the cylindrical indentions extends nearly halfway across applicants fins 4.

That is to say, applicant uses dies so made that eflicient than a core as constructed in accordance with said Patent 1,442,565. In the first place thecylindrical indentions 2, when the core strips are placed in position, form water tubes 10 which sponding water tube 21 of said patent. In and of itself this would hardly be surprising but it also has been found from actual experimentation that a higher degree of heat transfer is obtained notwithstanding the fact that more water is permitted to course through the tubes. .This may also be augmented by the fact that some of" the water from the tube 10 is permitted to enter the space 6 of each fin 4 and thus come more positively and intimately into heat transferring contact with the separator strips 15 whereby the heat from the water is given up more readily to the air passing through the cells 8. Still another reason for this increased efiiciency lies in the are of larger cross sectional area than the corre-' cells is more positively broken up, interrupted or otherwise disturbed so that more molecules of said column will come into contact with the metal of the core. In other words, applicants indentions 2 extend further into each air cell 8 than do the corresponding indentions of the patented construction and therefore when the column of air seeks to pass through each cell the outer molecules of said column will contact with the indentions 2, be deflected thereby from the straight course through the core and be caused to travel obliquely across the air cell, the places of such molecules being taken by molecules from other portions of the column. It thus results that the molecules in the outer area of the column become heated first and their positions are then changed by the indentions 2 so that the cooler molecules from the center of the column can take their place and receive heat from the metal of the core.

Another improvement in this construction over that of Patent 1,442,565 lies in the formation of the rows of indentions in pairs. In other words, and particularly with reference to Fig. 5 the row 25 of indentions is so spaced from its companion row 26 of said indentions that there are left in between said rows areas of the plane of the main body portion of the strip, said areas constituting ridges 2'7, common. to both rows but which do not extend into the water tube 10 so far that they will meet the ridges on the opposite strip forming the other half of the water tube thus making possible a space 28 through which water may pass in a lateral direction. Also the abutments 3 previously described are not soldered but on the other hand the abutments of the opposite strips merely come into surface contact whereby a more rigid construction is made possible, and squashing of the radiator core substantially prevented. In other words, the abutnients 3 do not so tightly fit against each other that they will not permit a small amount of water to pass laterally from one water tube into another but they do fit to the extent that the rigidity of the core is increased. This is of high value because very often obstructions are formed in water tubes from foreign particles such as rust scales and the like which would be sufficient in size to close such a water tube as shown in said patent. This is made practically impossible, however, in the present construction due to the enlargement of said tube and also due to the fact that should an obstruction occur in one portion of the water tube 10 the following column of water could pass around said obstruction laterally through the space such as 28 into other portions of the water tube.

In actual tests a core made in accordance with this construction has been found to dissipate more heat per pound of metal and per gallon of flow constructions heretofore proposed and including that of said Patent 1,442,565. In fact the efficiency is approximately 8% more over said patented construction. Therefore With radiators of 400 square inches frontal area and a depth of approximately 4 inches for the same amount of heat dissipation it was found that the cost of material alone of a core made in accordance with this invention was $1.40 less than the cost of the material of the other radiator. Stated in other words, not only is there an actual difference in construction but this construction has led to actual increase in efficiency at a reducion in the cost of the materials.

In the preceding construction it should be stated that the pre-crirnped strips forming the water tubes as well as the separator strips associated therewith are preferably formed of extremely thin metal and in practice they are made of brass as well as copper. The ends of each core strip after the same is formed into the core unit, are soldered together. After the parts have been assembled to form the entire core a clamp is placed around the assembly and pressure applied to hold the parts in tight contacting engagement. The core with the encompassing clamp is then laid in a bath of solder so that the entire surface 12 will take up the solder and thus secure the core as a unifiedmass. The assemblage is then turned over and the other side immersed so that the solder may affect the surfaces 12 of the opposite sides of the radiator all as will be readily understood. The clamp is removed after the solder has cooled and the unified radiator mass placed within its encompassing shell and thus made ready for attachment to the radiator chassis.

It is obvious that those skilled in the art may vary the details of construction and arrangements of parts constituting the article, as well as the steps and combinations of steps constituting the method without departing from the spirit of the invention and therefore it is not desired to be limited to the foregoing except as may be demanded by the claims.

What is claimed is:

1. The herein described radiator unit com,- prising a strip of sheet metal folded to provide a plurality of straight edged fins, the portions of said sheet between said fins provided with axially aligning cylindrically formed indentions, the cylindrical planes of said indentions extending substantially half way through each fin, and edges formed on said sheet between said fins adapted to join said unit to a similarly formed unit, whereby a plurality of straight-flow water passages are formed by the indentions of the adjoining units.

2. The herein described radiator unit comprising a strip of sheet metal folded to provide a plurality of straight edged fins closed at their ends but having a slight open taper therebetween, the portions of said sheet between said fins provided with axially aligning indentions constituting one half of a water conduit composed of plural passages extending substantially half way through each fin and in fluid conducting relation with the open space of each fin, and edges formed on said sheet between said fins adapted to join said unit to a similarly formed unit.

3. The herein described radiator unit comprising a strip of sheet metal folded to provide a plurality of fins having double tapered walls and a straight edge fold, said fins closed tightly at their ends but spaced between said walls, the portions of said sheet between any two fins provided with vertically disposed fluid conducting indentions,

said indentions in alignment with similarly formed indentions in the sheet portions between the other fins, the planes of the walls of said indentions extending substantially half way through each fin, said indentions communicating with the interior space of each fin, and crimped edges formed on said sheet between said fins for joining said unit to a similarly formed unit, the indentions of the joined units forming a complete water tube of plural passages through the radiator.

same comprising two halves, each half formed of sheet material stamped and folded to provide a plurality of spaced doubled walled fins and a plurality of passage forming indentions, the walls 4. A fluid conducting passage for a radiator the outwardly in a straight fold and haying their ends closed. V

6. A radiator cooling element comprising a plurality of parallel fluid conducting passages and a plurality of parallel heat radiating fins extending laterally therefrom, said fins formed. by straight folds of the material constituting the said element, said passages formed in halves joined together at their sides, the passage formation of each half passing through each of the fins of said half.

WELLINGTON W. MUIR. 

